Hertel 18571 Countersink 1/8 in 90 Degree 4 Flute Hss

Product Description

The HERTEL 18571 is a straight-shank countersink designed for creating conical seat profiles in metal and similar materials prior to fastener installation. Built from high speed steel, it features a 90-degree included angle and four flutes that provide clean, controlled cutting action. The head diameter measures 0.125 inches (1/8 inch), matched by a straight-cylindrical shank of the same diameter. This tool is suited for bench drilling, drill press work, and hand-held drilling applications where consistent countersink depth and finish are required. Machinists, maintenance technicians, and fabrication professionals reach for this size when working with smaller fastener clearances.

The HERTEL 18571 is used in light-duty machining and fabrication environments where 90-degree countersinks are required for flat-head fastener seating. Its compact 1/8-inch head and shank diameter make it appropriate for small-bore applications in sheet metal, aluminum, brass, and mild steel. It fits standard drill chucks and collet holders that accept straight-cylindrical shanks of 1/8-inch diameter. Typical applications include aerospace maintenance, general metalworking, and fixture assembly where precise countersink geometry is critical to fastener flush-fit.

Key Features

• 90-degree included angle for standard flat-head fastener seating
• Four flutes provide smooth cutting and chip clearance
• High speed steel construction for durability across a range of metals
• Straight-cylindrical shank fits standard drill chucks and collets
• 1/8-inch head and shank diameter suited for small-fastener applications

Compatibility

Designed as a direct-fit countersink for any standard drill chuck or collet holder accepting a 1/8-inch straight-cylindrical shank.

Installation Notes

Secure the shank fully in the chuck or collet before use to prevent runout. Power down the drill press or secure the handheld drill trigger before changing tools. Use appropriate cutting fluid when working with harder metals to extend tool life. Inspect flutes for wear or chipping before each use and replace if cutting edge integrity is compromised.